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1.
Bone marrow aspirates (BMAs), owing to their innate osteogenic potential, are well-documented supplements to osteoconductive and/or osteoinductive materials. The calcaneal body provides foot and ankle surgeons a convenient harvest site with low morbidity and minimal cost. In the present study, we sought to identify and characterize multipotent mesenchymal stromal cells (MSCs) in BMAs harvested from the human calcaneal body. Ten healthy patients aged 18 to 65 years were enrolled in the present study. BMAs were harvested from the patients without any reported postoperative complications related to the harvest. Cells isolated from all the aspirates were adherent to culture plates and expressed positive MSC surface markers (CD105, CD90, and CD73) and a low level of negative MSC markers (CD34 and CD45). The cells maintained the ability to proliferate and differentiate into cells of mesenchymal lineages. The BMAs from the human calcaneal body offer a healthy source of multipotent MSCs.  相似文献   
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骨缺损治疗需要可降解的生物相容性好的有骨诱导能力的材料,脱矿牙本质基质(DDM)就是一种理想的骨替代材料.DDM来源于人类不行使功能的牙齿,其牙本质经过脱矿、冲洗、冻干和磨碎等工序就可制备.牙本质和牙槽骨在化学成分上非常接近,这就为以DDM作为骨的支架提供了条件.骨形态发生蛋白(BMP)是一种可诱导新生骨形成的生长因子,DDM中富含BMP.DDM在诱导新生骨的形成过程中无宿主免疫排斥反应,是一种有效的生物相容性良好的骨移植材料.DDM的制备有传统制备和超声-酸蚀制备两种方法.脱矿在传统制备中就是一个好方法,脱矿后的牙本质保存了牙本质原始结构物质.粒径也是影响成骨效果的一个因素,75~500 μm的粒径为多数学者所认同.在超声-酸蚀制备中,利用超声-酸蚀技术对DDM的表面结构进行改性,可有效地创造出利于细胞和生长因子吸附的表面结构.  相似文献   
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The aim of this study was to evaluate and compare the influence of a piezoelectric device versus a conventional bur on osteocyte viability and osteoblast and osteoclast activity using an in vivo mouse model. Osteotomies were created and bone grafts were harvested using either a conventional bur or a piezoelectric device; the resulting injuries and bone grafts were evaluated over an extended time-course using molecular and cellular assays for cell death (TUNEL assay), cell viability (4′,6-diamidino-2-phenylindole (DAPI) staining), the onset of mineralization (alkaline phosphatase activity), and bone remodelling (tartrate-resistant acid phosphatase activity). Osteotomies created with a piezoelectric device showed greater osteocyte viability and reduced cell death. Bone grafts harvested with a piezoelectric device exhibited greater short-term cell viability than those harvested with a bur, and exhibited slightly more new bone deposition and bone remodelling. The difference in response of osteocytes, osteoblasts, and osteoclasts to bone cutting via a bur and via a piezoelectric device is negligible in vivo. Given the improved visibility and the margin of safety afforded by a piezoelectric device, they are the instrument of choice when cutting or harvesting bone to preserve soft tissue.  相似文献   
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Statins are potent inhibitors of cholesterol synthesis. Several statins are available with different molecular and pharmacokinetic properties. Simvastatin is more lipophilic than pravastatin and has a higher affinity to phospholipid membranes than atorvastatin, allowing its passive diffusion through the cell membrane. In vitro studies on bone marrow stromal cells, osteoblast‐like cells, and embryonic stem cells have shown statins to have cholesterol‐independent anabolic effects on bone metabolism; alas, statins were supplemented in osteogenic medium, which does not facilitate elucidation of their potential osteoinductive properties. Embryonic stem cells (ESCs), derived from the inner cell mass of the blastocyst, are unique in that they enjoy perpetual self‐proliferation, are pluripotent, and are able to differentiate toward all the cellular lineages composing the body, including the osteogenic lineage. Consequently, ESCs represent a potentially potent cell source for future clinical cellular therapies of various bone diseases, even though there are several hurdles that still need to be overcome. Herein we demonstrate, for the first time to our knowledge, that simvastatin induces murine ESC (mESC) differentiation toward the osteogenic lineage in the absence of osteoinductive supplements. Specifically, we found that a simvastatin concentration in the micromolar range and higher was toxic to the cells and that an effective concentration for osteoinduction is 0.1 nM, as shown by increased alizarin red staining as well as increased osteocalcin and osetrix gene expression. These results suggest that in the future, lipophilic simvastatin may provide a novel pharmacologic agent for bone tissue engineering applications. © 2010 American Society for Bone and Mineral Research.  相似文献   
6.
目的 探讨脱矿牙本质基质(DDM)诱导成骨机制的细胞理论框架和成骨方式。方法 在24只新西兰大耳白兔双侧竖脊肌区制备4个肌袋位点,随机选取3个位点为实验位点,植入DDM,另一位点为对照位点,不植入任何材料。术后1、2、3、4、8、12、16和20周处死动物,制作组织标本,应用苏木精-伊红(HE)染色、抗酒石酸酸性磷酸酶(TRAP)染色和免疫组织化学染色对间充质干细胞、成骨细胞、软骨细胞及破骨细胞进行鉴定分析。结果 HE染色显示:3周时,实验组可见软骨样基质、骨样基质和成骨样细胞。免疫组化染色显示:各时间点CD44、碱性磷酸酶(ALP)和Ⅱ型胶原表达有统计学意义(P<0.05)。结论 DDM具有良好骨诱导性和组织相容性,其诱导成骨的主要方式可能为软骨内成骨。  相似文献   
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选用免32只,手术截除桡骨2cm。缺损区充填DGB,手术后2、3、6、9周分别杀死动物作光镜及电镜观察。结果在电镜下发现有三类细胞,即成骨系、破基质系细胞和血管内皮细胞,并见到非成骨性结缔组织的间充质细胞分化为前成骨细胞→成骨细胞→骨细胞以及其同时分化为血管内皮细胞的全部过程。表实验从组织学和细胞学二方面证实DGB确有诱导成骨的作用。  相似文献   
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BACKGROUND AND OBJECTIVE: Bone morphogenic proteins are known, in animal models, to promote many developmental processes, including osteogenesis. Clinical trials are currently underway to evaluate the potential of bone morphogenic proteins to promote bone and periodontal regeneration in humans. The aim of this study was to establish an optimal cell culture condition for using to study the biological effects of recombinant human bone morphogenic protein-2 on periodontal ligament cells. MATERIAL AND METHODS: The roles of serum concentration, types of culture medium (alpha-modified essential medium or Dulbecco's modified Eagle's medium), the presence of osteoinductive medium (including dexamethasone, ascorbic acid and beta-glycerophosphate), and timing of addition of the osteoinductive medium and recombinant human bone morphogenic protein-2, on the expression of alkaline phosphatase were investigated in cultured periodontal ligament cells. Cytochemical stainings and biological assay of alkaline phosphatase were also demonstrated. RESULTS: Our results suggested that an increased concentration of serum might mask the effect of recombinant human bone morphogenic protein-2 on the expression of alkaline phosphatase in periodontal ligament cells. alpha-Modified essential medium was found to induce a stronger cytochemical staining of the alkaline phosphatase than Dulbecco's modified Eagle's medium under similar culture conditions. Pre-incubation of cells with osteoinductive medium before the addition of various concentrations of recombinant human bone morphogenic protein-2 enhanced greater alkaline phosphatase expression than the simultaneous presence of both osteoinductive medium and recombinant human bone morphogenic protein-2. CONCLUSION: The findings of this study suggest that the effect of recombinant human bone morphogenic protein-2 on periodontal ligament cells could be efficiently investigated after the proper selection of culture variables and temporal sequence of adding bioactive factors. The optimal culture condition identified in this study might be useful in further studies to elucidate the regulatory mechanism of periodontal ligament cells in periodontal regeneration after stimulation with recombinant human bone morphogenic protein-2.  相似文献   
9.
OBJECTIVE: To evaluate the effects of various 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) on ectopic osteoinduction by recombinant human bone morphogenetic protein-2 (rhBMP-2) using different administration methods. MATERIALS AND METHODS: Disks containing 5 mug of rhBMP-2 and type I collagen were implanted into the calf muscles of 6-week-old male rats (n = 64). Either the lactone form of simvastatin (SV), open hydroxy-acid form of simvastatin (SVA), cerivastatin (CVA), or vehicle (control) was then administered per orally (PO group) or subcutaneously (SC group) for 20 days. The disks were removed on day 21 after implantation, and ectopic induced bone formation was evaluated by radiographic, histologic, and biochemical analysis. RESULTS: Both the projected and radiopaque area on X-ray film, and the calcium content of the SV group in the SC group (SV-SC group) were significantly greater than those in the other SC and PO groups. Alkaline phosphatase activity and tartrate-resistant acid phosphatase activity in the SV-SC group were significantly lower than those in the other SC and PO groups. Histologic examination revealed an increase of ectopic induced bone volume in the SV-SC group. CONCLUSION: Subcutaneous administration of SV stimulates ectopic osteoinduction by rhBMP-2 through reduction of bone turnover.  相似文献   
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Aim To assess whether human dentine has the potential to promote the development of calcified tissues when implanted in the muscle tissue of mice. Methodology Root canals in extracted human teeth were instrumented to produce dentine fragments. The dentine fragments produced were divided into two. In group 1, fragments were demineralized and sterilized. In group 2, the fragments were not submitted to any additional treatment. The dentine fragments were then implanted in the muscle of mice. In group 3, the muscles were implanted with rehydrated lyophilized human bone powder. Animals were killed following test periods of 7, 15, 30, 60, 120 and 180 days, the fragments were removed together with adjacent muscle and examined under light microscopy to assess calcification. Results Areas of calcification were observed in groups 1 and 3 after a period of 180 days. In group 2, the surrounding tissues displayed only chronic inflammatory infiltration. Conclusions On the basis of the experimental model adopted in this study, fibroblast-rich connective tissue formed in groups 1 and 3, which could reflect an osteoinductive process. Further studies are suggested to identify which dentinal factors are capable of inducing the formation of a calcified matrix.  相似文献   
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